1. Field of the Invention
The present invention relates to a lubricating device for an engine (internal combustion engine) that can be installed in a portable work machine or the like.
2. Description of Related Art
An engine installed in a portable work machine, such as a brush/weed cutter, may include a crank chamber, in which the pressure varies as a piston moves up and down, and an oil sump chamber which is disposed beneath the crank chamber and that retains lubricating oil. Such an engine is disclosed in JP 2004-293448 A. According to the engine disclosed in JP 2004-293448 A, a crank chamber and an oil sump chamber are in communication through an opening part, and the oil mist generated in the oil sump chamber is supplied to the crank chamber through the opening part.
Note that various types of engines are installed in portable work machines. The standard rotational speed (operating condition) or the shape of the oil sump chamber varies according to the engine type. Accordingly, it is required to optimize the amount of oil mist generated in the oil sump chamber according to the engine type.